Centrifugal pump unit



Sept. 28, 1954 Jfarafar and Lez/fl Con/ra! B. C. BOECKELER CENTRIFUGALPUMP UNIT Filed NOV. 19 1949 FIG'.v I

BY 75W (9., mi fw/M' ATTORNEYS Patented Sept. 28, 1954 `U N TI TED ,STATE S CENTRIFUGAL PUMP UNIT Benjamin Clark 4Bocclrele `signor Vto TheHydrojet 11 (Claims.

This invention relates to centrifugal pumps-and vacuum pumps and has forits principal object the provision of a pump unit comprising incombination a centrifugal pump and a vacuum pump in which thecentrifugal pump is self-priming. In a preferred embodiment of myinvention I provide a self-primingcentrifugal pump unit with but asingle moving part in a compact structure of exceptionalsimplicity Thecombination of my invention lls the need Afor a simple, lei'licient andtrouble-free pump unit to pump various liquids, for example, water andchemicals, notably volatile liquid fuels such as gasoline or petrol, andsolvents.

My invention comprises a centrifugal pump having an impeller, Aand avacuum pump having a shell for confining a liquid annulus which isrotatable on the impeller shaft and a jet pump, and a duct connecting.the suction side of the centrifugalpump Vwith the jet pump to removeair, gas or vapor (hereinafter called gas) from the suction side ofthepump and prime the pump. Advantageously I mount the impeller of thepump with its suction and discharge chambers and the shell for confiningthe liquid annulus in a compact integral housing. The combination valsoincludes means to supply liquid to the annulus, preferably by duct,means connected to the centrifuga'l pump, and means for removing excessliquid from the annulus to maintain 'it at a uniform depth. The shelland its annulus are within a chamber evacuated by the jet pump land theduct for priming the pump connects the chamber with the suction side ofthe vcentrifugal pump.

One of the important 'features of my invention is the provision of a jetpump mounted in a stationary operating position inside the shell toreceive rotating liquid from the annulus to create the vacuum and .suckgas from the intake rersuction side of the centrifugal pump and thus.prime the pump.

The centrifugal pump and the vacuum pump are preferably enclosed withina housing including a vacuum chamber in which the shell rotates, asuction chamber for the centrifugal lpump between the ,impeller and thevacuum chamber, and aliquid discharge vchamber for the centrifugal pump.,Advantageously the shaft on which' the impeller and shell are mountedpasses through a partition which divides vacuum and Vsuction chamberswith such a clearance as to provide a free passage ,for Agas but arestricted passage for liquid. The Asuction Aside of the jet pump opens1113.0 :and eva-cuates the' vacuum chamber and the r, Trenton, Mich.,as-

Corporation, Trenton,

Delaware passageway around .the fshaft provides an annular duct for theflow of gas :in priming the 4centrifugal pump and thereafter arestricted passageway for the iiow of liquid tto supply the annulus withmake-up liquid. ,The liquid thus flowing yfrom the suction chamber ofthecentrifugal pump enters the liquid annulus land means :are provided toremove ythe excess liquid and return it tothe liquid circuit. 'The gasseparated by the iet-pump is vaccompaniedibyffa certain -amount of-liquid which Ais discharged from the pump. Means are also provided vforthe separation Iof the gas and liquid and the return ofthe liquid to4the -system when desired, yas-fwhen `chemicals or Yfuels arebeingpmnped, l

My combination of pumps may be Iconstructed and arranged with the commonshaft .in either a vertical or .a horizontalposition For convenience inillustrating Ythe invention, the drawings show a combination with avertical drive shaft together Ywith .means in the shell fto trap a ybodyof .starting liquid. y l d These and yother (objects v.of the inventionwill be better .understood `.after considering the Vfollowing discussiontaken in `conjunction with the accompanying drawings, 4in which:

Fig. 1 lis a sectional elevation of a self-priming centrifugal pump unitembodying the invention, and

Fig. I2 is a sectional of Fig. 1.

In the embodimentof -the invention illustrated in Figs. 1 and 2, thehousing :l encloses .a vacuum chamber 2 ,asuction or inlet .chamber vi,-an outlet or discharge chamber 4 for fthe centrifugal pump, a .gasseparating chamber .5, and a liquid discharge outlet port 6. Chamber 5is provided for pumps intended for pumping `,such liquids as gasolinewhere gas or vaporeli-mination is .necessary. For other 'liquids chamberA'i maybe eliminated. AChamber 2 is closedrby the cover l in which ismounted the combined :shaft bearing and stuffing .box 8,.- The lcover I0closes the lower part of the centrifugal `pump discharge chamber 4 andvhas the thrust v`bearing Il mounted there- The drive ,shaft .|\2..is ina vertical position in the embodiment of `-aizzparatus shown, is mountedin the said bearings,and is `driven in the usual way by .an electric,motor not shown. The fannular-shelll and pump impeller I4 rare xed tothe shaft and rotate therewith. The shell 'pro vides an annular chamberand has acentral opening 15 vwithin the upturned -lip I6 which forms :aretainer forthe body of liquid l-l when view along line 2 2 3 the pumpis at rest (Fig. l). When the shaft is rotating at operating speed, theliquid annulus I8 assumes the position shown in Fig. 2.

The collar is xed to the housing and there is a sufficient clearance 20between it and the shaft to provide a relatively free passage for theflow of gas but a restricted passage for the flow of the liquid. With a0.500 inch diameter shaft, for example, an effective opening is about0.525 inch. The jet pump 2| is attached to the collar as by Welding andis held in a fixed position. The vacuum pump may be constructed toembody features as more particularly described and claimed in mycopending application Serial Number 128,265, filed November 19, 1949,now Patent No. 2,632,597, to achieve relatively low vacuums and highefficiency. The vacuum pump shown comprises an inlet opening 22 in theliquid annulus I8, and a jet pump 23 with a gas inlet 24 for sucking gasout of the vacuum chamber 2 and creating a reduced pressure therein. Thecurved portion 25 causes a centrifugal separation of the gas and liquidand the baiiie 2E aids in directing the liquid back to the annulus andthe gas, with some liquid, through tube 2i into the separator and levelcontrol 28. Gravity also aids in separating the gas and liquid. Theskimmer is mounted in a fixed position in the housing and serves toremove excess liquid from the liquid annulus and return it to thesuction side of the centrifugal pump. The suction chamber 3 of the pumphas a liquid inlet 3| to which is connected a tube 32 for the return ofliquid from the separator. Tube 32 may be branched as 32' shown inbroken lines to return a part of the liquid back to the annulus andthereby assure a supply of operating liquid. Moreover line 32 mayconnect to an outside or independent source of liquid to provide aliquid annulus which is independent of the liquid being pumped. In sucha modification the shaft clearance can be smaller and line 32 is notconnected to the liquid inlet. An orifice is inserted in the tube 32 tocontrol the flow of liquid from the separator back to the centrifugalpump.

The discharge chamber 4 of the centrifugal pump connects to a laterallydisposed but somewhat elevated pocket or chamber 5 into which gasaccompanying the discharge liquid may rise and escape under pressurethrough tube 34 to the separator 28. The liquid being pumped passeslaterally to the outlet port 6.

When the pump is constructed for operation with a vertical shaft, avalve is necessary in the liquid outlet. If the pump should be startedwith the suction and discharge chambers empty, it is necessary to closethe valve, otherwise the valve may be open.

When the pump is first set in motion, the liquid assumes the positionshown in Fig. 2 and is forced to iiow through the jet pump 23. Most ofthe liquid returns to the annulus while some liquid and the gas suckedout of chamber 2 through duct 24 are forced to iiow to the separator 2t.By reason of the reduced pressure in chamber 2, gas is sucked out of thesuction chamber 3 through the clearance between the shaft and collar 2D,resulting in liquid being drawn in through port 3I, and the pump is thusprimed. When the centrifugal pump is in operation, some liquid is suckedthrough the shaft clearance by reason of the lower pressure in chamber 2than in chamber 3 and spills over the top of the collar entering theshell I3 to make up for liquid lost through tube 21. The excess liquidis skimmed off the annulus and returned by skimmer 30 to to the suctionchamber. In operation there is a little spillage of liquid from theannulus and this collects in the bottom of chamber 2. Scoops 36 are sopositioned and shaped that they scoop the liquid olf the bottom andreturn it to the annulus.

Any gas or vapor which accompanies a liquid, such as the vapor ofgasoline, enters the chamber 5 from which it iiows under pressurethrough tube 34 to the separator 28. The separator may be equipped witha fioat controlled valve to maintain some liquid in the separator andallow the gas to escape without returning to the pump. The orifice 35can serve this purpose. If the gas separated is inert like air, then itmay be allowed to escape to the atmosphere. If it is a dangerous oruseful gas, it may be recovered as by passing it from the separatorthrough an activated carbon or like adsorber (not shown).

I claim:

l. A. self-priming liquid pump unit comprising a liquid pump, a suctionchamber communicating with. the intake of the liquid pump and having anintake for liquid thereto, a vacuum chamber, a vacuum pump including ajet pump stationarily mounted in said vacuum chamber, means for formingin said vacuum chamber a rotating annulus of liquid, the vacuum pumphaving an inlet positioned to receive liquid from said rotating annulusof liquid, means for conducting liquid entering said inlet to the jetpump, a gas inlet for the jet pump communicating at one side with thespace of the vacuum chamber to be evacuated and at its other side withthe jet pump at a position to have gas from said space of the vacuumchamber drawn therethrough when liquid is passed through the jet pump,and a duct connecting the vacuum cha-mber with said suction chamber forevacuation ci the suction chamber to cause liquid. to flow through theinlet thereto and prime the liquid pump.

2. A pump unit as defined in claim 1 in which the inlet for the vacuumpump is positioned to lie within the rotating annulus of liquid.

3. A pump unit as defined in claim l in which the duct connecting thevacuum chamber with the suction chamber is of such size as to permitready flow of gas therethrough in priming of the pump, but to restrictliquid dow therethrough.

4. A pump unit as defined in claim l in which the suction chamber ispositioned between the vacuum chamber and the liquid pump chamber, acommon partition separates the vacuum chamber from the suction chamber,'the liquid pump is mounted on a rotatable shaft which passes throughsaid partition and said cl'lamoers, and said shaft carries means forforming said annulus of liquid.

5. A pump unit as defined in claim 41. in which the duct connecting thevacuum chamber with the suction chamber is a clearance space around saidrotatable shaft where it passes through said common partition.

6. A self-priming liquid pump unit comprising a liquid pump, a suctionchamber communicating with the intake of the liquid pump and having anintake for liquid thereto, a vacuum chamber, a vacuum pump, including ajet pump, 5tationarily mounted in said vacuum chamber, a drive shaft onwhich said liquid pump is mounted, said drive shaft passing through saidchambers,

a shell for receiving liquid mounted on said driveshaft within saidvacuum chamber for rotation With said shaft, means for maintaining asupply of liquid within said shell, the vacuum pump having an inletpositioned to receive liquid from a rotating annulus of liquid caused byrotation of said shell, means for conducting liquid entering said inletto the jet pump, a gas inlet for the jet pump communicating at one sidewith the space of the vacuum chamber to be evacuated and at its otherside with the jet pump at a position to have air from said space of thevacuum chamber drawn therethrough when liquid is passed through the jetpump, and a duct connecting the vacuum chamber with the suction chamberfor evacuation of the suction chamber to cause liquid to flow throughthe inlet thereto and prime the liquid pump.

"1. A pump unit as defined in claim 6 in which the duct connecting thevacuum chamber with the suction chamber is of such size as to permitready ow of gas therethrough in priming of the pump, but to restrictliquid flow therethrough.

8. A pump unit as dened in claim 6 which includes means for removingexcess liquid from the rotating annulus of liquid.

9. A pump unit as dened in claim 6 in which a common partition separatesthe vacuum chamber from the suction chamber, the drive shaft passesthrough said partition, and the duct connecting the vacuum chamber withthe suction chamber is a clearance space of about 0.025 inch around saiddrive shaft where it passes through said common partition.

` the central opening in the shell and a conduit for passing gas drawnfrom the vacuum chamber by the jet pump passes through said opening to apoint outside of the unit.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 1,591,388 Jennings July 6, 1926 1,981,965 Morgan Nov. 27, 19342,134,686 DeLancey Nov. 1, 1938 2,153,360 Auger Apr. 4, 1939 2,166,530Morgan July 18, 1939 2,178,994 Inglis Nov. 7, 1939 2,260,600 BoeckelerOct. 28, 1941 2,295,024 Boeckeler Sept. 8, 1942 2,368,528 Edwards Jan.30, 1945 2,440,912 Parker May 4, 1948 2,444,100 Hill June 29, 19482,461,865 Adams Feb. 15, 1949

